Today, fabrics are made from a wide variety of natural fibers, such as cotton, synthetics, and combinations thereof. The basic fabric is a greige fabric that must be dyed in order to provide the desired color to the resultant fabric and/or garment. Many dye compositions and methods have been proposed for dyeing fabrics; however, most have proven costly in terms of materials, labor, and processing time.
One conventional dyeing method, known as yarn dyeing, involves dyeing individual fibers or yarns prior to the fibers or yarns being sewn, knitted, or woven into a fabric. A significant problem associated with this method is the substantial inventory requirement to maintain a supply of the various colored yarns needed to produce textile products, and the prohibitively high inventory costs resulting therefrom.
Another conventional dyeing method is known as bulk dyeing. In bulk dyeing, un-dyed fibers or yarns are knitted or woven into a raw, or undyed, fabric. The raw fabric is subsequently scoured or bleached, and then dyed.
Common bulk dyeing methods include vat dyeing, beam dyeing, jet dyeing, and bath dyeing. Vat dyeing typically consists of immersing a piece of fabric in a vat of liquid dye. Beam dyeing involves winding a length of fabric about a perforated beam. The beam is then placed in a vessel where dye is pumped into the center of the beam, out of the perforations, and through the fabric. Jet dyeing involves placing the fabric in a high-pressure, high-temperature kettle of liquid dye. Bath dyeing involves immersing the fabric in a bath of dye in a rotating drum.
There are a number of problems, however, associated with bulk dyeing methods. First, the bulk dyeing process necessitates large volumes of water, which increases the costs of the bulk dyed fabrics, and has an adverse impact on the environment. Also, some of the dyed fabric must be cut away from templates during the manufacture of a garment from the fabric. Since the bulk fabric has already been dyed, this results in increased costs due to the wasted dye and fabric.
A more significant problem with bulk dyed fabrics in the manufacture of garments is the unpredictability of consumer color preferences. In the garment industry, changes in consumers' preferences for one color over another color can lead to an overstock of the undesired colored garments and a back-order of the desired colored garments.
Other methods of dyeing fabrics involve printing dyes onto a surface of a fabric. These methods are commonly used to apply a decorative pattern on the surface of the fabric. Such printing methods include screen-printing and inkjet printing. While these methods have proven useful in quickly changing from one decorative pattern to another, they have not proven useful for large scale production of fabrics or garments.
Perhaps one of the most cost-effective methods of dyeing a fabric is spray dyeing. Spray dyeing, as used herein, includes conventional spraying as well as atomization and electrostatic applications. However, a problem with spray dyeing is providing a uniform dye on both sides of the fabric. Normally, to achieve such uniformity requires spray dyeing on both sides of the fabric or garment in a very controlled environment. Also, the fabric or garment must remain in a taut position in order to provide a flat and even distribution of color on the fabric or garment. This is difficult to achieve in large scale production, and not cost-effective, especially if both sides of the fabric or garment are to be dyed.
Accordingly, there is a need for a dye composition and resultant method of dyeing cellulosic, such as cotton, greige, scoured, or bleached fabrics that provide uniform color on both sides of the fabric. It is particularly important to provide such a composition that will dye cellulosic fabrics to any desired color in one basic spray step or operation.